Light-sensitive, aminopyridinediazonium salt compositions



United States Patent 3,134,675 LIGHT-SENSITIVE, AMINOPYRIDINEDIAZONIUM SALT COMPOSITIONS Ralph G. D. Moore, Chenango Forks, and Robert J. Cox, Chenango Bridge, N.Y., assignors to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware N0 Drawing. Original application Sept. 30, 1958, Ser. No. 764,242, now Patent No. 3,082,200, dated Mar. 19, 1963. Divided and this application May 9, 1962, Ser. No. 193,602.

16 Claims. (Cl. 9691) The present invention relates to aminopyridinediazonium salts and, more particularly, to the use of said salts in the diazotype process.

The diazotype process, as is known, involves sensitization of a base such as paper or the like with a light-sensi tive diazo compound, exposing the sensitized material under a pattern to burn out the diazo where the light strikes and developing an image by coupling the undecomposed diazo with an azo dye coupling component in the presence of a base such as ammonia, sodium hydroxide or the like. The speed and overall utility of the process depend upon the rapidity and degree that the diazonium compound is burned out on exposure, the rapidity with which the diazo couples to form azo dye and the density of dye image obtained.

Many diazonium-compounds have been recommended for use in manufacturing diazotype materials. For the most part, these diazos are derived from p-phenylenediamines. While these compounds produce satisfactory materials for the diazotype process, they still leave much to be desired from the standpoint of the speed of the material, the density of the images and the rate of development.

We have now found that diazonium compounds which meet the prerequisites of the diazotype art to a very high degree are aminopyridinediazonium salts in which the amino group is secondary or tertiary. Such diazonium compounds and their use in light-sensitive diazotype materials constitute the purposes and objects of the present invention.

The diazonium salts contemplated herein may be typified by the following structural formulae:

in which R, is hydrogen, alkyl such as methyl, ethyl, propyl, butyl or the like, aryl of the benzene series such as phenyl, tolyl, diethylaminophenyl, dimethylaminophenyl or the like, pyridyl or aralkyl, such as benzyl and R may be alkyl as above, aryl as above, pyridyl, or aralkyl as above; Z represents the atoms necessary to complete a 6- membered hydrogenated heterocyclic ring system; R is 3,134,675 Patented May 26, 1964 hydrogen or alkyl as above; X is an anion such as halide, sulfate, nitrate or the like; and Y is diphenyl or benzylphenyl.

Examples of the compounds within the above formulae which we have found to be eminently suitable are:

6 dimethylamino 3 pyridinediazonium chloride and its zinc chloride, stannic chloride, cadmium chloride, mercuric chloride, boron trifluoride double salts 6 diethylamino 3 pyridinediazonium chloride and its its aforementioned double salts 6 methylamino 3 pyridinediazonium chloride and its aforementioned double salts 6 ethylamino 3 pyridinediazonium chloride and its aforementioned double salts 6-morpholino-3-pyridinediazonium chloride 6-piperazino-3-pyridinediazonium chloride 6-benzyla'mino-3-pyridinediazonium chloride 6-p-toluidino-3-pyridinediazonium chloride 6 (p dimethylaminoanilino) 3 pyridinediazonium chloride N,N' (4,4' biphenylene)bis(6 amino 3 pyridinediazonium chloride) 6-anilino-3-pyridinediazonium chloride 6- 2-pyridylamino -3-pyridinediazonium chloride 6,6 (p,p' methylenedianilino)bis(3 pyridinediazonium chloride) N-methyl 6 anilino 3 pyridinediazonium chloride 6 dimethylamino 5 methyl 3 pyridinediazonium' chloride 2-dimethylamino-3-pyridinediazonium chloride The couplers with which the diazonium salts were used are those normally employed in diazotype materials. Below is a listing of couplers which can be used with our diazonium compounds and the color produced therewith:

Coupler: Dye Color Resorcinol Sepia. 6,7 dihydroxy 2 naphthalenesulfonic acid Reddish purple.

2,3 naphthalenediol Reddish purple. Acetoacetanilide Yellow. Phloroglucinol Reddish brown. m-hydroxyphenylures Sepia. N-benzylacetoacetamide Yellow.

3-methyl l-phenyl-S-pyr'azolone Orange.

N omethoxyphenyl 3 hydroxy- 2-naphthamide Blue-purple.

4,4'-thiodiresorcinol Red to sepia.

In preparing our novel compounds, we have found it to be generally more convenient to form the double salt of the compound and an inorganic salt such as, for example, zinc chloride, stannic chloride, cadmium chloride, mercuric chloride, boron trifluoride, and many others and to isolate our novel compounds in the form of such double salts.

Below we have given a number of examples of our novel compounds and processes for their preparation. It is to be understood, however, that these examples are given by way of illustration only and not by way of limitation.

EXAMPLE I 6-Dimethylamin0-3-Pyridinediazonium Chloride A solution of 1.7 g. of 5 amino 2 dimethylaminopyridine hydrochloride in 10 ml. of hydrochloric acid (sp. gr. 1.19) was cooled with stirring to 0 C. and treated dropwise with 5 M sodium nitrate at 0-5 C. until an excess of nitrite remained in the solution. About 2 g. of solid stannic chloride pentahydrate were added, whereupon a yellow solid precipitated which was filtered and dried. It melted at C. with decomposition and 3 was probably a complex salt of the diam with the following structure:

5 amino 2 dimethylaminopyridine hydrochloride was isolated in 78% yield by the reduction of 2.19 g. of Z-dimethylamino 5 nitropyridine in 50 ml. of isopropyl alcohol under 3-4 atmospheres of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and anhydrous hydrogen chloride was passed into the solution to precipitate the amine hydrochloride which was recrystallized from an isopropyl alcohol-water mixture. It melted at 260 C. with decomposition.

2 dimethylamino 5 nitropyridine, M. 154-5 C.,

was obtained by nitration of 2 dimethylaminopyridine, B. 81-85" C./15 mm., which was prepared by methylation of 2-aminopyridine with dimethyl sulfate and sodamide (Ber. 61, 429).

EXAMPLE II 6-Methylamino-3-Pyridinediaz0nium Chloride 5 amino 2 methylaminopyridine hydrochloride was prepared by the reduction of 8.9 g. of 2-methylamino-5- nitropyridine in 200 ml. of ethanol under 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and anhydrous hydrogen chloride was passed into the filtrate until a dark precipitate appeared. The precipitate was filtered and washed, first with ethanol, then with ether. It weighed 7.6 g., which corresponds to a yield of 67%, and melted at 239-41 C. with decomposition.

2-methylamino-5-nitropyridine, M. ISO-1 C., was prepared in 92% yield by the action of methylamine on 2- chloro 5 nitropyridine, M. 1068 C., which in turn was prepared from 2-aminopyridine by nitration, diazotization, hydrolysis and finally reaction with phosphorus pentachloride (J. Chem. Soc. (1941, 12).

EXAMPLE III fi-Morpholino-3-Pyridinediazonium Chloride A slurry of 10 g. of 5-amino 2 morpholinopyridine hydrochloride in 10 ml. of hydrochloric acid (sp. gr. 1.19) and 15 ml. of water was cooled to C. with stirring. 11.6 ml. of M sodium nitrite were added dropwise, not allowing the temperature to rise above 5 C. 3 g. of stannic chloride pentahydrate were added to the yellow solution and a yellow brown solid precipitated. Stirring was continued for one-half hour and after standing in the cold overnight, the precipitate was filtered, washed with a brine solution and dried. It weighed 4.7 g., melted at 162 C. with decomposition, and probably had the structure:

NzCLVSnCh 5 amino 2 morpholinopyridine hydrochloride was prepared in yield by hydrogenating 2 morpholine- S-nitropyridine in ethanol at 3-4 atmospheres pressure over palladium on carbon catalyst. The catalyst was filtered off and anhydrous hydrogen chloride was passed into the filtrate until a white solid precipitated which melted at about 250 C. with decomposition.

2 morpholino 5 nitropyridine, M. 142-3 C., was prepared in 75% yield by reaction of morpholine with 2- chloro 5 nitropyridine prepared as outlined in Example II,

EXAMPLE IV 6-Piperazin0-3-Pyridinediaz0nium Chloride A solution of 3.1 g. of 5 amino 2 piperazinopyridine hydrochloride in 5 ml. of hydrochloric acid (sp. gr. 1.19) and 5 ml. of water was cooled to 0 C. with stirring and treated with 2 g. of stannic chloride pentahydrate. Then 2.2 ml. of 5 M sodium nitrite were added dropwise, the temperature not being allowed to rise above 5 C. Stirring was continued for 15 minutes and the yellow product was collected by filtration, washed with water, and dried. It weighed 1.5 g., melted at 160 C. with decomposition, and probably had the structure:

N- N omen,

5 amino 2 piperazinopyridine hydrochloride Was made in 76% yield by the reduction of 3.3 g. of 2-piper azino S nitropyridine in ethanol at 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and a white solid was precipitated by passing anhydrous hydrogen chloride through the filtrate. It melted over the range 240-45 C. with decomposition.

2 piperazino 5 nitropyridine, M. 84-5 C., was prepared in 24% yield by reaction of piperazine with 2- chloro-S-nitropyridine obtained as in Example II.

EXAMPLE V 6-Benzylamino-3-Pyridinediazonium Chloride A solution of 6.5 g. of 5 amino 2 benzylaminopyridine hydrochloride in 2.2 ml. of hydrochloric acid (sp. gr. 1.19) and ml. of water was cooled to 0 C. with stirring and was treated with 6 ml. of 5 M sodium nitrite. The solution was allowed to stir for one-half hour and then 10.5 g. of stannic chloride pentahydrate were added and the yellow solid that precipitated was collected by filtration and dried. It weighed 6.4 g., melted at C. with decomposition, and probably had the structure:

I {Aid /Such lid/11 MH- 5 amino 2 benzylaminopyridine hydrochloride was prepared in 89% yield by the reduction of 7.4 g. of 2- benzylamino 5 nitropyridine in 250 ml. of isopropyl alcohol at 3-4 atmospheres of hydrogen pressure over palladium on carbon catalyst. The catalyst was filtered off and anhydrous hydrogen chloride was passed into the filtrate. A white solid was precipitated by the addition of about one liter of ether. It melted over the range 210- 20 C. with decomposition.

2 benzylamino 5 nitropyridine, M. 131-4" C., was prepared in 51% yield by the condensation of benzylamine with 2-chloro-5-nitropyridine prepared as in Example II.

EXAMPLE VI 6-p-Toluidino-3-Pyridinediaz0nium Chloride A solution of 8.3 g. of 5-amine-2-p-toluidinopyridine hydrochloride in 25 ml. of hydrochloric acid (sp. gr. 1.19)

and 75 ml. of water was cooled to C. with stirring. 7 ml. of M sodium nitrite was added dropwise, the temperature not being allowed to rise above 3 C. To this solution were added 30 ml. of 60% zinc chloride solution and the stirring was continued for one-half hour. The yellow solid which precipitated was filtered and dried. It weighed 10.8 g., melted at 137 C. with decomposition, and probably had the structure:

S-amino-Z-p-toluidinopyridine hydrochloride was prepared in 82% yield by reduction of 2-p-toluidino-5-nitropyridine in ethanol at 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and anhydrous hydrogen chloride was passed into the filtrate until a white solid precipitated. It melted over the range 237-42" C. with decomposition.

2-p-toluidino-S-nitropyridine, M. 136-70 C., was prepared in 68% yield by condensation of p-toluidine with 2- chloro-S-nitropyridine (Example II).

EXAMPLE VII 6-(p-Dimethylaminoanilino) -3-Pyridinedlazonium Chloride A solution of 8.5 g. of S-amino-Z-(p-dimcthylaminoanilino)-pyridine hydrochloride in 15 ml. of hydrochloric acid (sp. gr. 1.19) and 35 ml. of water was treated slowly with 6.5 ml. of 5 M sodium nitrite. To this solution were added 20 ml. of 60% zinc chloride solution and stirring was continued for one-half hour. The yellow product was filtered and dried. It weighed 9.0 g., melted at 128 C. with decomposition, and probably had the structure:

EXAMPLE VIII N,N'-(4,4'-Biphenylene) his(6-A mine-3- Pyridinediazonium Chloride 2 g. of N,N'-bis(5-nitro-2-pyridyl)benzidine were slurried with 12.5 ml. of hydrochloric acid (sp. gr. 1.19) and 12.5 ml. of water. Zinc powder was added portionwise with continued stirring until a very pale yellow solution was obtained. The excess zinc was filtered off and ice was added to the filtrate until the temperature had dropped to 5 C. This solution was treated dropwise with 5 M sodium nitrite until it showed free nitrite ion. The orange yellow precipitate was filtered and dried. It weighed 0.5 g., melted at 106 C. with decomposition, and probably had the structure:

Crude N,N-bis(5-nitro-2-pyridyl)benzidine, which did not melt at 320 C., was prepared in almost quantitative yield by the condensation of benzidine with 2-chloro-5- A solution of 9.1 g. of 5-amino-2-anilinopyridine hydrochloride in 25 ml. of hydrocloric acid (sp. gr. 1.19) and ml. of water was cooled with stirring to 0 C. This solution was treated with 20 ml. of a solution of zinc chloride and then slowly with 7.9 g. of 5 M sodium nitrite solution. The reaction mixture was stirred for one-half hour and then allowed to stand in the cold overnight. The yellow precipitate was filtered, washed with a little water, and dried. It weighed 9.9 g., melted with decomposition at 128 C., and probably had the structure:

00H NH 5-amino-2-ana1inopyridine hydrochloride was prepared in 76% yield by the hydrogenation of 2-anilino-5-nitropyridine in ethanol at 34 atmospheres pressure over palladium on carbon catalyst. The catalyst was filtered oil and anhydrous hydrogen chloride was passed into the filtrate until a white solid precipitated, which was filtered, washed with ether, and dried. It melted with decomposi tion over the range 21923 C.

2-anilino-5-nitropyridine, M. 1347 C. (Ann. 518, 27489 (1935)), was prepared in 54% yield by the action of aniline on 2-chloro-5-nitro-pyridine (Example II).

EXAMPLE X 6-(2-Pyridylamino)-3-Pyridinediazonium Chloride A slurry of 1.5 g. of 5-amino-2-(Z-pyridylamino)-pyridine hydrochloride with 5 ml. of hydrochloric acid (sp. gr. 1.19) and 15 ml. of water was cooled in an ice bath. 1.3 ml. of 5 M sodium nitrite were slowly added with stirring and the resultant yellow solution was treated with a few milliliters of 60% zinc chloride solution. The yellow precipitate was filtered, washed with a little water, and dried. It weighed 2.1 g., melted at C. with decomposition, and probably had the structure:

5-amino-2-(Z-pyridylamino)pyridine hydrochloride was prepared in 98% yield by the reduction of 2-(2-pyridylamino)-5-nitropyridine in isopropyl alcohol under 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst wasfiltered off and a few drops of hydrochloric acid (sp. gr. 1.19) were added to the filtrate. The white solid which precipitated was collected.

2-(2-pyridylamino)-5-nitropyridine was prepared according to Chichibabin and Preobrazhenskii (Ber. 61, 203 (1928)) by the action of Z-aminopyridine on 2-chloro- S-nitropyridine (Example II).

EXAMPLE XI 6,6 (p,p'-Methylenedianilino) bis(3-Pyridinediaz0nium Chloride) A solution of 1.7 g. of 5,5'-diamino-2,2'-(p,p-methylenedianilino)dipyridine hydrochloride in 7.5 ml. of hydrochloric acid (sp. gr. 1.19) and 7.5 ml. of water was cooled to 0 C. with stirring. About 0.5 g. of zinc chloride was added to this solution and it was filtered. The filtrate was treated with 1 ml. of 5 M sodium nitrite solution and allowed to stand in the cold for one-half hour. The yellow precipitate was filtered and dried. It p obably had the structure:

5,5 diamino-2,2'-(p,p'-methylenedianilino)dipyridine hydrochloride was prepared by the reduction of 3.4 g. of 5,5 dinitro 2,2-(p,p'-methylenedianilino)dipyridine in 200 ml. of ethanol and 50 ml. of acetone under 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and the filtrate was treated with a few drops of hydrochloric acid (sp gr. 1.19). 1.7 g. of a solid which darkened at 200 C. and melted at 235 C. with decomposition were isolated.

5,5 dinitro 2,2-(p.p'-methylenedianilino)dipyridine, M. 203-7 C., was obtained by the condensation of p,p'- methylenedianiline with 2-chloro-5-nitropyridine (Example II).

EXAMPLE XII N-Methyl-6-Anilin0-3-Pyridinediaz0nium Chloride A solution of 2.3 g. of N-methyl-Z-anilino-S-nitropyridine in 200 ml. of isopropyl alcohol was reduced under 3-4 atmospheres pressure of hydrogen over palladium on carbon catalyst. The catalyst was filtered off and the filtrate was treated with a few drops of hydrochloric acid (sp. gr. 1.19) and then drowned in an excess of ether. The white precipitate was very hygroscopic and could not be easily handled in air. It was, therefore, dissolved in 5 ml. of hydrochloric acid (sp. gr. 1.19) and 5 ml. of water, cooled to C. with stirring, and treated slowly with 2 ml. of M sodium nitrite solution. The addition of a few ml. of concentrated stannic chloride solution precipitated a yellow solid which after trituration with ether was filtered and dried. It weighed 3.0 g., melted with decomposition over the range 145-7 C., and probably had the structure:

| ourm-O-momsmn N-methyl-Z-anilino-S-nitropyridine, M. 102-4 C., was prepared by condensation of N-methylaniline with 2-chloro-5-nitropyridine (Example II).

EXAMPLE XIII 6-Dz'methylamino-S-Methyl-3-Pyridinediazonium Chloride A solution of 3.0 g. of 5-amino-2-dimethylamino-3- methylpyridine hydrochloride in 2.5 ml. of hydrochloric acid (sp. gr. 1.19) and 2.5 ml. of water was cooled with stirring to 0 C. and treated with 3.2 ml. of 5 M sodium nitrite below 5 C. About 2 ml. of a concentrated stannic chloride solution were added and the mixture was stirred for about one-half hour. The yellow precipitate was filtered, washed with a little water, and dried. It weighed 4.0 g., melted with decomposition over the range 1357 C., and probably had the structure:

* Thiourea 8 2-r'imethylamino-3-methyl-S-nitropyridinc. M. 181-91 C., was prepared by the condensation of dimethylamine with 2-chloro-3-methyl-F-nitropyridine in 96% yield.

2-chloro-3-methyl-5-nitropyridine, B. 144-9/ 19 mm., was prepared from 2-arnino-3-methylpyridine in 46% yield (J. Org. Chem. 14, 328-32 (1949)).

EXAMPLE XIV 2-Dimethylamin0-3-Pyridinediaz0nium Chloride A solution of 6 g. of 3-amino-2-dimethylaminopyridine hydrochloride in 15 ml. of hydrochloric acid (sp. gr. 1.19) and 15 ml. of water was cooled to 0' C. with stirring. A solution of 8.6 ml. of 5 M sodium nitrite was added slowly to the solution which took on a deep red color. Five ml. of 70% zinc chloride solution were added and the orange-colored product was filtered, washed with a little Water, and dried. It weighed 2.1 g., melted at -90" C. with decomposition, and probably had the structure:

3-amino-2-dimethylaminopyridine hydrochloride, B. 111 C./ 12 mm., was prepared from 3-amino-2-chloropyridine as outlined by Rudy and Majir (Ber. 71B, 1328 (1938)).

3-amino-2-chloropyridine, M. 755-77 0., was preared from 3-aminopyridine according to Ber. 69B, 2593- 2605 (1936).

Certain of the compounds produced in accordance with the above examples were tested by incorporating them together with couplers in a sensitizing solution, coating the solution on a base, exposing the coating to actinic light under a positive original and then developing the exposed coating. These tests are described in the following examples:

EXAMPLE XV A solution was made up of the following compositions:

Acetone ml 35 Methanol ml 55 2-methoxyethyl acetate m.l 10 Sulfosalicylic acid g 1.0 g 0.5 Zinc chloride g.... 0.4 N-o-methoxyphenyl-3-hydroxy-2-naphtharnide g 2.0 6-dimethylamino-3-pyridinediazonium chloridezstannic chloride (Ex. I) g 1.6

This solution was bead-coated on cellulose acetate base.

This diazotype material was then exposed under a positive original to actinic light and developed with moist ammonia vapors. A positive diazotype image of purple hue and with a clean White background resulted. A solution prepared by substituting 2.0 g. of m-hydroxyphenylurea for the N-o-methoxyphenyl-3-hyclroxy- 2-naphtharnide and reducing the amount of 6-dimethylamino 3 pyridinediazonium chloride:stannic chloride from 1.6 g. to 1.0 g. was similarly coated on cellulose acetate to give a positive-Working diazoztype material. In this case, the image hue was a rich orange-sepia.

EXAMPLE XVI The following solution was coated on cellulose acetate base:

Acetone ml 35 Methanol ml 55 2-methoxyethyl acetate ml 10 Sulfosalicylic acid g 1.0 Thiourea g 0.5 Zinc chloride g 0.4 rn-Hydroxyphenylurea g 2.0 6 anilino 3 pyridinediazonium chloridezzinc chloride IX) g 1.6

The intensely yellow colored product was exposed to actinic light under a positive'originai. The yellow color bleached Where light struck, and the positive image was developed with moist ammonia varors. The resultant diazotype was orange-yellow on a white background and had good reprint opacity to actinic light.

A diazotype of essentially the same characteristics was prepared by substituting 6-p-toluidino-3-pyridinediazonium chloridezzinc chloride (Ex. VI) for 6-anilino-3- pyridinediazonium chloride:zinc chloride in the above formulation.

EXAMPLE XVII A solution of the following composition was coated on cellulose acetate film base:

Acetone ml 35 Methanol ml 55 Z-methoxyethyl acetate ml. Sulfosalicylic acid g 1.0 Thiourea g 1.0 Zinc chloride g 0.5 m-Hydroxyphenylurea g 2.0

6 dimethylamino s methyl 3 pyridinediazonium chloridezstannic chloride (Ex. XIII) g 1.2

ll Ra and wherein R is selected from the class-consisting of hydrogen, lower alkyl, aryl of the benzene series, dialkylaminophenyl pyridyl and benzyl; R is selected from the class consisting of lower alkyl, aryl of the benzene series, dialkylaminophenyl pyridyl and benzyl; R is selected from the group consisting of hydrogen and lower alkyl; Z represents the atoms necessary to complete a hydrogenated 6-membered heterocyclic nucleus; Y is selected from the class consisting of diphenyl and benzylphcnyl; and X is selected from the class consisting of an inorganic anion forming the simple aminopyridinediazonium salt and an inorganic anion having attached thereto an inorganic salt selected from the group consisting of zinc chloride; stannic chloride, cadmium chloride, mercuric chloride and 10 boron trifluoride f rming the double salt of the aminopyridinediazonium salt and the inorganic salt.

2. A light-sensitive diazotype material containing a.-

coupling component and as a light-sensitive diazonium compound a 6-dim.-thy]umino-3-pyridinediazonium chloride.

3. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-methylamino-3-pyridinediazonium chloride.

4. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-morpholino-3-pyridinediazonium chloride.

5. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-piperazino-3-pyridinediazonium chloride.

6. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-benzylamino-3-pyridinediazonium chloride.

7. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-p-toluidino-3-pyridinediazonium chloride.

8. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-(p-dimethylaminoanilino)-3-pyridinediazonium chloride.

9. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound an N,N'-(4,4'-biphenylene)bis(6-amino-3-pyridincdiazonium chloride).

10. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-anilino-3-pyridinediazonium chloride.

11. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-(2-pyridylamino) 3-pyridinediazonium chloride.

12. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6,6-(p,p'-methylenedianilino)bis(3-pyridinediazonium chloride).

13. A light-sensitive diazotype material containing a. coupling component and as a light-sensitive diazonium compound an N methyl 6 anilino 3 pyridinediazonium chloride.

14. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium compound a 6-dimethylamino-5-methyl-3-pyridinediazonium chloride.

15. A light-sensitive diazotype material containing a coupling component and as a light-sensitive diazonium cfiimpound a 2-dimethylamino-3-pyridinediazonium chlon e.

16. The article as defined in claim 1 wherein the value for X in the aminopyridinediazonium salt is Cl.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Saunders: The Aromatic Diazo Compounds, Edward Arnold & Co., London, 1949, page 54.

Venkataraman: Synthetic Dyes, vol. I, Academic Press, N.Y., 1952, pp. 234-235. 

1. A LIGHT-SENSITIVE DIAZOTYPE MATERIAL CONTAINING A COUPLING COMPONENT AND AS A LIGHT-SENSITIVE DIAZONIUM COMPOUND AND AMINOPYRIDINEDIAZONIUM SALT SELECTED FROM THE CLASS CONSISTING OF THOSE HAVING THE FOLLOWING GENERAL FORMULAE: 